Conical paper cup with rounded bottom



June 21, 1949.

W. E. AMBERG MMZM June 2l, 1949. w. E. AMBERG 2,473,840

CONICAL PAPER CUP WITH RQUNDED BOTTOM Filed Dec. 4, 1947 3 Sheets-Sheet 2 June 2l, 1949.

5 Sheets-Sheet 3 Filed Dec. 4, 1947 Patented June 2l, 1949 Walter E. Amberg, Beverly Shores, Ind., assigner to Lily-Tulip Cup Corporation, a corporation of Delaware Application December 4,1947, serial Ne. '189,608

2 claims. (onzas-1.5)

1 This invention relates to paper cups of the dispensable type and to a cup of this general type of general conical form but with the bottom rounded to a substantial distance from the apex of the cone from which theA cup is formed.

An object ofthe invention is to create a bottom to a conical cup of less than sixty degree angle whereby all substances served therein may b e accessible to a conventional household spoon.

Another object of this invention is to provide an improved paper cup of less than sixty degree angle consisting of an acute angled frustroconical side wall merging at its smaller end in a pleated bottom. The pleated bottom of the paper cup is sufliciently large to make the entire bottom accessible to a spoon and to direct the motion of fluid in the cup when agitated for suspending dissolvable fluids in the cup to aid the mixing thereof. Preferably, the bottom of the paper cup is formed by gathering into pleats the paper of an appreciable portion of the side wall of a conical paper cup at the apex end thereof.

Other objects of the invention are to provide a cup of this type in which the paper is most eco-l similarly formed cups for shipping.

Still another object of the invention is to provided a cup of this character in which the bottom is nished with'a water resistant impregnationv l which gives added strength to the cup bottom.

These and other features of the invention will be seen from the following detailed specification read in connection with the accompanying drawings forming part thereof and in which- Figure 1 shows a strip of blanks from which one type of cup is formed:

Fig. 2 shows a cup in the early stages of fabrication;

Fig. 3 shows a cup completely formed before rounding the bottom;

Fig. 4 shows a cup mounted upon a male die in position for descent of the female die;

Fig. 5 shows a cup being formed between the male and female dies;

Figs. 6-11, show a cup in successive stages of formation of the rounded bottom;

Fig. 12 shows a cup completely formed;

Fig. 13 shows a modied form of cup with rolled or beaded lip;

Fig. 14 shows a fragmentary vertical section'of the rounded bottom of the cup; f'

Fig. 15 shows a cup pleated witha modified form of pleat in the vertical direction;

Figs. 16 and l17 show horizontal sections of.

vertically pleated cup bottoms; v

Fig. 18 shows a vertical section of a vertically pleated cup bottom; and

Fig. 19 shows a horizontal section of a vertically pleated cup bottom taken on the line lil- IQ of Fig. 18. l

lThe rounded bottom cup Dispensable paper cups of thel conical type are widely used to provide a sanitary receptacle at soda fountains, in restaurants, in work gangs, and in the home. The side walls of cups of this type are normally formed in the shape of a cone with a very sharp apex, as the paper at the apex is usually more than one ply in thickness and .brought to a il'rm and sharp point. This pointed cup apex not only presents a definite hazard in the handling and use of cups of this type but also forbids the use of a spoon to remove the nal content of the cup as the pointed portion of the cup remains inaccessible to a vspoon and lalso produces vortices when the contentsv of the cup are stirred, which prevent dissolving of much of any solid content which may be in the liquid in the cup. The pointed portion of the cup' usually also serves to collect the solid portion of the content of the cup and prevents its removal either by stirring or by means of a spoon.

These dimculties, .encountered in the use of the ordinary conical paper cup, are eliminated if a substantial portion of the conical 4side walls at the apex end of the cup can be deformed and the cup provided with a bottom which is sufficiently large to make it accessible to a spoon and so alters the characteristic motion of the uid in the cup when-stirred asto insure that the solids will be most readily 'dissolved and will not settle out into an inaccessible portion of the cup.

Afrom a continuous strip 2li and is formed` into a conical paper cup in the manner disclosed ln the aforementioned patents by rolling the blank about a conical mandrel which moves about its apex at the point 22 so that the blank edge 23 forms the lip of tbe cup and the concave edge 3 24 forms the inner cup seam, while the straight blank edge 26 forms the outer cup seam, as shown in Figs. 2 and 3. The formed side wall of the cup is maintained as a cone by means of the adhesive strip 25 by which the free edge of the blank is secured to the body of the cone.

The cone, as finally formed by the method to be hereinafter described. assumes the shape shown in Fig. 12 in which the conical apex of the originally formed cup has been manipulated, deformed and compressed into the rounded bottom 21, which is the characteristic novelty of this cup. The side wall of the cup becomes frustro-conical and merges at its smaller end in s. rounded bottom having appreciable vertical and horizontal internal radii.

If desired. the rounded bottom may be further strengthened and the cup improved by the use of a water resistant impregnation at the lower end of the cup such as that indicated by the numeral 28. This impregnation may be of wax or any vof the so-called plastic materials which are water resistant and will readily bond to paper and can be manipulated and compressed with the paper in the method of forming the rounded bottom which is hereinafter outlined.

'I'he impregnation may be applied to the cup blank during its process of formation or the apex portion of the completed conical cup mail1 be immersed in the impregnation material prior to the further deformation and rounding of the cup bottom. The addition of the water resistant material not only strengthens the cup and increases its durability in use with the cup lled with liquid, but also gives the cup a smoother and more finished appearance than is possible with paper alone.

The method of forming the cup 'I'he method of forming the rounded bottom is indicated in Figs. 4-11 inclusive of the drawings and may be generally described as the formation of a series of pleats at the apex portion of the cup and then compressing this pleated portion of the cup into the rounded form of bottom desired in the nal cup.

In Fig. 4 the cup 29 is shown mounted upon a suitable conical male mandrel 30. Surmounting the cup is shown the female die member 3l with the plunger 32 about to engage the apex portion of the cup. The female and male dies are designed to form a complementary matrix for the cup and will vary in, construction according to the manner to be pursued in forming the pleats.

One form of die for performing the method herein described is that shown. described and claimed in my copending application Serial No. 7,558, led February 11, 1948.

'Ihe dies are preferably so arranged as to lform a single pleat at one time.- This pleat may be either formed by simple compression dies or may be formed by spinning the conical cup about suitable mandrels so as to form the pleats successively.

In Fig. 5 the dies shown in Fig. 4 have been brought together in the rst stage of performing the method hereinfurther described.

In Fig. 6 the cup 29 is shown after a single application of a die to form the pleat 33 at about the line at which the rounded bottom is to be formed upon the cup. v

In Fig. '1 the cup 29 has been again treated either by compression dies or by spinning, to form the second pleat 2l, while in Figs. 8, 9, 10 and 11 further stages of this work are shown .4 resulting in the addition of successive pleats 35, 36 and 31, and -as shown in Fig. 11, the final compression of the apex of the conical cup at 3l.

'I'he number of pleats is immaterial but it is important that they be small so as not to bunch or pile up substantial portions of the paper cup body into small areas.

After the cup has been formed into the form shown in Fig. 11, a round die may be applied so as to compress the plurality of pleats into a continuous rounded bottom, as shown.

The manner in which the pleats are finally arrangedvin the formation of the cup bottom is shown in the fragmentary section of the cup bottom, Fig. 14, in which the successive pleats are shown folded over and compressed to form a fairly smooth, rounded cup bottom.

In Fig. 13 is shown a modified form of the paper cup in which the lip 43 has .been rolled into a beaded cup lip. This beading is usually -performed after the conical cup has been formed and this may be done either before or after rounding of the cup bottom, as described.

While the pleating shown in Figs. 6-12 is horizontal or circumferentially disposed, the cup bottom may be rounded by a similar method in which vertical or longitudinally disposed pleats are formed at the apex of the cup. In either case, however, the paper at the apexial end of the conical cup is circumferentially gathered to form the cup bottom. This alternative is shown in Figs. 15-19. The cup |29 is creased vertically by suitable dies to form the creases |33. These may be formed in various ways, such as creasing the entire area of the apex portion of the cup, as shown in Fig. 16, or by equally spaced creases between substantially unaltered portions of the cup wall, as shown in Fig. 17. After formation of these creases the entire creased lower end of the cup is compressed between suitable dies to round the cup bottom and form the pleats |34, shown in Fig. 19.

The method herein disclosed distributes the paper forming the cup bottom in a uniform manner and prevents the formation of crude irregularities in the cup bottom wall and weakening of the cup bottom by crushing of the irregularly distributed paper. The pleating of the paper in the manner outlined accumulates the excess paper into regular folds of fairly equal thickness, avoids any undue strain on any portion during formation, and thus strengthens the rounded bottom appreciably.

While the method of forming this cup has been described as accomplished by compression dies, it is obvious that various other means may be employed to form the step of successively pleatlng the portions of the cup which are to be deformed and pressed into the rounded cup bottom.

Having thus shown and described several embodiments of the invention, it is to be understood that it is capable of many modifications. For example, the bottom of the truncated conical paper cup of this invention as well as being rounded may be of other desired shape such as substantially concave for producing the benecial results of the invention. Changes, therefore, in the construction and arrangement may be made without departing from, the spirit and scope of the invention as disclosed in the ap pended claims, in which it is intended to claim all novelty inherent in the invention as broadly as permissible, in view of the prior art.

I claim as my invention:

1. A truncated conical single piece paper cup o! less than sixty degree angle comprising an acute angled substantially smooth frustro-conical side wall and a substantially inner concave spoon serviceable pleated bottom merging with the side wall, said bottom only having a plu- 5 rality of circumferentially disposed apexially 6 the pleats being substantially concentric with the axis of the cup.

WALTER, E. AMBERG.

REFERENCES CITED The following references are of record in the iile of this patent:

UNITED STATES PATENTS lo Number Name Date 772,258 Shea Oct. 1l, 1904 1,206,708 Hutchins Nov. 28, 1916 2,104,535 Barbieri Jan. 4, 1938 2,147,805 Windsor Feb. 2l, 1939 2,220,312 Barbieri Nov. 5, 1940 2,235,349 Amberg Mar. 18, 1941 2,272,308 Merta Feb. l0, 1942 

